From patchwork Mon Feb 13 17:41:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Matteo Cascella X-Patchwork-Id: 1741811 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=RPp8EXoJ; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4PFs920WhPz23hX for ; Tue, 14 Feb 2023 04:41:56 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pRcpZ-0003ee-7d; Mon, 13 Feb 2023 12:41:33 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pRcpX-0003eV-34 for qemu-devel@nongnu.org; Mon, 13 Feb 2023 12:41:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pRcpU-0007Ms-Mr for qemu-devel@nongnu.org; Mon, 13 Feb 2023 12:41:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1676310087; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=BvY4zgEB8OftJv+2jHv8qui2lBTfZZcHg6u/DZaQs0g=; b=RPp8EXoJ6n7477w5ya4Oe99FzcFjKJZShIU7YnZLIGCzN++TsB7a0foPIYZXuapXZ69Dpr IUq0mCKoLIhW94b8vOSZsl2T/gQne+ZP/b0/pQGpIMVoDaD1otC2B2S+o9slYlbgs7XwtE E5fHEiRnXRyMwQVOF/Kh5DPakPzGbj4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-259-nugUuWHdM_SljrPmR1VGog-1; Mon, 13 Feb 2023 12:41:22 -0500 X-MC-Unique: nugUuWHdM_SljrPmR1VGog-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 433DF86C169 for ; Mon, 13 Feb 2023 17:41:21 +0000 (UTC) Received: from f37-work.redhat.com (unknown [10.39.193.233]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 917BE492B03; Mon, 13 Feb 2023 17:41:20 +0000 (UTC) From: Mauro Matteo Cascella To: qemu-devel@nongnu.org Cc: mcascell@redhat.com, kraxel@redhat.com Subject: [PATCH] usb/dev-wacom: fix OOB write in usb_mouse_poll() Date: Mon, 13 Feb 2023 18:41:13 +0100 Message-Id: <20230213174113.591632-1-mcascell@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; envelope-from=mcascell@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org The guest can control the size of buf; an OOB write occurs when buf is 1 or 2 bytes long. Only fill in the buffer as long as there is enough space, throw away any data which doesn't fit. Signed-off-by: Mauro Matteo Cascella Reported-by: ningqiang1 Reported-by: SorryMybad of Kunlun Lab Tested-by: Alexander Bulekov --- hw/usb/dev-wacom.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/hw/usb/dev-wacom.c b/hw/usb/dev-wacom.c index 7177c17f03..ca9e6aa82f 100644 --- a/hw/usb/dev-wacom.c +++ b/hw/usb/dev-wacom.c @@ -252,14 +252,20 @@ static int usb_mouse_poll(USBWacomState *s, uint8_t *buf, int len) if (s->buttons_state & MOUSE_EVENT_MBUTTON) b |= 0x04; - buf[0] = b; - buf[1] = dx; - buf[2] = dy; - l = 3; - if (len >= 4) { - buf[3] = dz; - l = 4; + l = 0; + if (len > l) { + buf[l++] = b; } + if (len > l) { + buf[l++] = dx; + } + if (len > l) { + buf[l++] = dy; + } + if (len > l) { + buf[l++] = dz; + } + return l; }